# Lesson video

In progress...

Hi, year six, welcome to our second lesson in our decimals and measures unit.

Today, we'll be looking at using, reading and writing standard units of length, mass and volume.

All you'll need for today is a pencil and a piece of paper.

Pause the video and get your equipment if you haven't done so already.

So, we'll be looking at using, reading and writing standard units of length, mass and volume.

Then, we'll look at selecting the correct unit of measure, then estimating and reading scales before you move on to some independent learning, and then a final quiz.

Pause the video now and complete the quiz and click restart once you're finished.

Great work, so now, here's your Do Now.

How might you group these units of measure, and what might you measure in each unit of measure? How do they compare to one another? Pause the video now and make some notes.

So, this is how you may have grouped them.

So, we've got altogether, the measures ending with litre, the ones ending with metre, and then the ones ending with gramme.

And you may notice that we've got some common prefixes.

So, here, we've got a prefix, kilo, kilometre and kilogramme.

Kilo means 1,000.

So, we can look at metres to kilometres, and we'll be looking at this in more detail in our next lesson.

But a kilometre is 1,000 metres.

And a kilogramme is 1,000 grammes.

Then we've got the common prefix, milli, millilitre and millimetre.

Milli means a thousandth.

So, a millilitre is a thousandth of a litre.

A millimetre is a thousandth of a metre.

And then we've also got our prefix, centi, which means a hundredth.

So, a centilitre is a hundredth of a litre, and a centimetre is a hundredth of a metre.

But we'll be looking at conversions in our next lesson.

So, let's look at our first group.

The first group are used to measure capacity or volume.

So, these are the sorts of things that you might measure the capacity or volume.

And if we look at millilitres, milli being a thousandth of a litre, we measure very small amounts in millilitres.

For example, a teaspoon has a capacity of five millilitres.

And there are a thousand millilitres in a litre.

Then we go on to centilitres, there are 100 centilitres in a litre.

But we don't often really talk about centilitres.

Then we'll think about, we usually talk about volume and capacity in millilitres and litres.

Half of a litre is 500 millilitres or 50 centilitres.

And a litre is used to measure larger capacities, such as a bucket or here, a paddling pool, which you may have had out over the weekend.

Now, if we look at the second group where we're looking at millimetre, centimetre, metre and metre, these are all used to measure distance or length.

So, here, we have some tools that we might use.

A ruler, a tape measure and a trundle wheel, which measure distance or length.

And we would measure something very small, like the length of a ladybird in millimetres.

Remember, that's a thousandth of a metre.

And a metre is roughly your arm span.

So, if you hold your arms out wide, that's roughly a metre.

We might measure the length of a book in centimetres.

A centimetre is a hundredth of a metre.

And then we might measure the width of a room in metres.

Kilometres is 1,000 metres.

So, one kilometre is 1,000 metres.

So, we measure longer distances in kilometres, such as the distance from Liverpool to London, which is approximately 340 kilometres.

The third group, grammes and kilogrammes are used to measure mass.

And this tells us the amount of matter in an object.

And we measure mass in grammes or kilogrammes.

And you'll often hear people referring to the weight of something but scientifically speaking, weight actually tells us the pull of gravity on an object, and that's measured in Newtons.

Mass and weight are used interchangeably, but it's mathematically correct to say mass.

And we will be looking at the difference between mass and weight in more detail in our fifth lesson in this topic.

So, kilogrammes and grammes are used to measure mass.

Now, here we have some tools for measuring mass, so some weighing scales.

And we measure things like food for recipes in grammes and kilogrammes.

We know that there's 1,000 grammes in a kilogramme because kilo means thousand.

And then just some good things to know, the mass of an apple is between 70 and 100 grammes.

The mass of a cat is about four kilogrammes, and the mass of an elephant is around 6,000 kilogrammes.

So, now, let's have a look.

Now, we know how to group these different units.

Let's have a look at selecting the correct measure, and estimating measures.

So, you have here in the blue boxes, different units of measure.

And I would like you to look at the items in the table, and decide which unit you would measure those things in.

So, pause the video and make some notes.

So, your first one, the mass of an average banana.

So, if we're thinking of mass, we're thinking of grammes or kilogrammes.

We know kilo is 1,000 so a kilogramme is 1,000 grammes.

But we know that a banana would not be measured in kilogrammes because it's too light.

So, we'd measure the mass of a banana in grammes.

And we'll go on to do estimated measure on our next slide.

The distance from London to Edinburgh.

So, if we're thinking about distance, we're thinking about metres, millimetres, centimetres, kilometres.

And I gave the example of Liverpool to London before, so we know that this is a long distance.

We would measure this one in kilometres.

Again, we're looking at length, millimetres, centimetres, metres or kilometres.

And I know that a ladybird is very small.

I would measure that one in millimetres.

It's less than one centimetre.

The length of a football pitch.

So, again, I'm on length, millimetres, centimetres, metres or kilometres.

I know that it's longer.

If I think about measuring a room in metres, I know that this is the correct unit to use because it's not, definitely not 1,000 metres, but it would be too difficult to measure in centimetres.

So, I measure this in metres.

The capacity of a drinking glass.

So, we're thinking of capacity now, so we're looking at millilitres, centilitres or litres, and I'd measure this in millilitres, as I think a drinking glass would be less than one litre, which is 1,000 millilitres.

The mass of an Asian elephant.

So, if I'm thinking mass, I'm thinking of grammes and kilogrammes.

And in on our previous section, we said that an apple was between 70 and 100 grammes.

So, I'm not going to measure the mass of an elephant in grammes, I'll use kilogrammes.

One kilogramme being 1,000 grammes.

The capacity of an egg cup.

Capacity, I'm using millilitres, litres, centilitres.

And that would be measured in millilitres.

The width of a tennis court.

Again, I would use metres.

The height of the Shard.

Although, it is a very tall building, it's definitely not 1,000 metres, which would be a kilometre.

So, this one, I would measure in metres.

I'll try that one again.

And then finally, the width of a pencil.

So, not the length of it, but the width across the pencil, I would measure in millimetres.

So, now, you're going to do some estimating.

So, you've got the same objects in your table.

You know the units that you're going to use.

But which of these measures is the approximate mass, capacity, or length of each of these items? Pause the video and match the approximate mass, capacity or length to the object.

So, we said we'd measure the mass of a banana in grammes.

And looking through these, I can see I've only got one with grammes.

So, the mass of an average banana is about 200 grammes.

So, that's a fifth of a kilogramme.

The distance from London to Edinburgh, we said we'd measure in kilometres.

We've only got one with kilometres, so that's approximately 650 kilometres.

The length of a ladybird, we said would be less than a centimetre, so we're measuring it in millimetres.

And I've got two millimetres very close to each other, so it could be either of these ones.

Either the six millimetres or eight millimetres.

And while we're on this one, let's see which other one we think would be measured in millimetres.

We said the width of a pencil.

So, for this one, again, we can say approximately six or eight millimetres.

Then, we'll look at the length of a football pitch.

And we're looking at metres here, so we've got three lots of metres.

And now, it might be good to compare here.

So, which other things were measured in metres? We had this one, the length of the football pitch measured in metres, the width of the tennis court and the height of the Shard.

Okay, so now, I need to start to reason which would be which.

Now, with the width of the tennis court, I know it is the smallest of those three, so I'm going to put 24 metres as the approximate width of the tennis court.

Then, I'm thinking about the length of a football pitch.

And I know that the Shard is taller than the length of a football pitch.

I think if you laid out football pitches next to each other, about three would be the height of the Shard.

So, I see that a lone football pitch is 100 metres.

And the height of the Shard therefore is 306 metres.

So, the height of the Shard is approximately three times the length of a football pitch.

So, I can get rid of these two.

Now, the capacity of the drinking glass was in millilitres.

I've got two here, 560 millilitres or 40 millilitres.

Well, remember that a teaspoon was five millilitres.

So, 40 millilitres is eight teaspoons which is not a lot, so that can't be the capacity of a drinking glass.

So, then it must be 568 millilitres.

And then I'll do my other millilitres, that must.

It's either the mass of an Asian elephant.

Well, you don't measure mass in millilitres, so it's not going to be that.

The capacity of an egg cup.

That seems more like you would be able to fit eight lots of five millilitre teaspoons into an egg cup.

And you could check that.

And then finally, we've got one left over, the mass of an Asian elephant, 4,000 kilogrammes.

So, there's our estimating done.

What I would encourage you to do is to see if you can prove some of those.

So, if you have a banana and some scales, check whether it is roughly 200 grammes.

If you have an egg cup, check whether you can fit about eight teaspoons of water in it because that's 40 mils.

And just see if you can prove some of these independently.

Now, we're going to look at reading scales.

So, in order to read a scale, we've got a really straightforward procedure.

So, what we do is we count the number of intervals, and then we divide the whole by the number of intervals.

So, here, the capacity of this container is 400 mils up to the line that we can see.

So, say we've got liquid in here up to here, that means that the whole is 400 mils.

Now, we count the number of intervals, the number of jumps up to 400 mils.

So, we've got one, two, three, four intervals.

So, we divide the whole by the number of intervals.

400 mils divided by four is equal to 100 mils.

So, each of these lines represents 100 millilitres.

So, I can write them on here.

100 millilitres, 200 millilitres, 300 millilitres, 400 millilitres.

Now, when you're counting your intervals, you need to be really careful because the mistake that some people make is that they count the number of lines.

So, they would say there are three intervals, and they would divide the whole by three.

But you need to count from the beginning, the jumps between the intervals.

So, be really careful when you're doing that.

We'll have a look at a few more together to make sure we don't make that mistake.

So, here, I have a tape measure, which is a type of scale.

And we're only given some of the numbers on the tape measure.

So, on the scale, you can see the intervals or the divisions, they are equal.

And our first question is what do the medium-sized lines represent? So, this one, for example, what does this line represent? And we'll answer this question first.

So, if we look here, we can see that the medium line here is between one centimetre and two centimetres.

And the interval from one centimetre to the medium line and to two centimetres is two jumps.

So, we are dividing the whole here, which is one centimetre by two.

So, one centimetre divided by two is 1/2 centimetre.

Or we might write it as 0.

5 centimetres.

So, we know that these medium lines represent 1/2 centimetre.

So, I can write that on here.

So, this line here represents 1.

5 centimetres.

This one would be 2.

5 and so on.

The next question is what do the smallest divisions on the scale represent? So, if I go to this one here, I know that this is zero here.

And I'm looking at how the whole, how many small lines are between zero and one centimetre.

So, there's one, two, three, four, five, six, seven, eight, nine, 10.

So, there's 10 intervals between zero and one.

So, we're doing one divided by 10 here, which is a tenth of a centimetre.

Or as a decimal, 0.

1 centimetres.

So, each of these small lines represent 0.

1 centimetres, which is the same as 1 millimetre.

And we're going to look more closely at conversions in our next lesson.

So, let's have a look at another scale together.

This time, the scale looks slightly different.

So, what you may want to do is pause and have a think about what each of these medium-sized lines represents before I talk through it.

So, if we look between the interval that we know, we see that between zero and 0.

5, there are five medium-sized intervals.

One, two, three, four, five.

So, we can see if we divide by five, each of these represents a fifth of 0.

5.

0.

5 divided by 5 is equal to 0.

1, and this is kilogrammes.

Or you may have already thought, well, 0.

5 kilogrammes is 1/2 a kilogramme, which is equal to 500 grammes divided by five is equal to 100 grammes.

So, 0.

1 kilogramme is equal to 100 grammes.

You can label these on here.

Each of these is a tenth of a kilogramme.

Or you may have written it in grammes.

500 grammes, 400 grammes and so on.

Okay, now, our next question is asking us about the smallest divisions.

So, if we look here between zero and 0.

1, we've got very small jumps.

But I can tell you that we've got one, two, three, four, five, six, seven, eight, nine, 10 jumps.

So, there are 10 of these.

10 intervals between zero and 0.

1 kilogrammes.

So, each one of these represents a tenth of 0.

1.

And we know that 0.

1 divided by 10 is equal to 0.

01 kilogrammes.

So, each of these small lines represents 0.

01.

And you may have linked that to grammes.

And you can see that if that's 100 grammes, each of these is 10 grammes.

Let's look at another one together.

We have another scale.

This one is again showing us grammes.

And we want to know where is the arrow pointing? So, we're looking between 300 and 400 grammes, The difference there is 100 grammes.

300 grammes, so 400 grammes take away 300 grammes is 100 grammes.

And we've got one, two, three, four, five, six, seven, eight, nine, 10 intervals.

100 divided by 10 is equal to 10.

So, each of these represents 10 grammes.

So, this one represents 300 grammes plus 10, 20, 30 grammes.

So, the arrow is pointing to 330 grammes.

So, you may want to now pause the video, and use that knowledge to tell me where's this arrow pointing to and this arrow pointing to? So, if each represents 10 grammes, this arrow is pointing to 410, 20, 30, 40, 50, 450 grammes.

And this arrow here is pointing to 200, 210, 220, 230.

So, the most important thing is to figure out what is the value of the scale that I'm looking at, and then how many intervals are there and divide the whole by the number of intervals.

So, now, it's your turn to pause the video, and read the scales, which number is each arrow pointing to? So, for the thermometer, we're looking between 10 and 20, so the gap here is 10.

We're looking at a 10 degree C gap with one, two, three, four, five interval.

10 divided by five is equal to two.

So, each of these small lines represents two degrees.

So, this is 10 degrees, 12 degrees, 14 degrees C.

And then on our ruler, we're looking between five and six, which is one, the difference between five and six is one.

And there are one, two, three, four, five, six, seven, eight, nine, 10 gaps or intervals.

One divided by 10 is 0.

1.

So, each one of these represents 0.

1.

So, this arrow is pointing to 5.

1, 5.

2, 5.

3 and this is in centimetres.

And you may have noticed the connection between centimetres and millimetres.

If this is one centimetre, then a tenth of it is one millimetre.

So, 5.

3 centimetres is equivalent to 53 millimetres.

Okay, it's time for you to complete some work independently.

So, pause the video and complete the task, and click restart once you're finished.

Straight on with question one.

You were asked to match the object to its approximate mass, capacity or length.

So, the first one was the capacity of the mug.

And you knew straight away capacity, you were looking for litres or millilitres.

And the approximate capacity of the mug is 350 millilitres.

Next one is the distance from Manchester to Glasgow, which was shown on the map at the side.

Again, distance, you're looking at metres or kilometres.

And it's a long distance here, so we're looking at kilometres, roughly 350.

The height of a male giraffe.

You're looking for metres or kilometres, centimetres, or millimetres.

So, the only one that works here is six metres.

And then you've got one left over, the mass of a blue whale is approximately 180,000 kilogrammes.

Question two, you were asked for the value of each arrow represented on the scale.

So, the first thing to have a look at is what each of the medium-sized lines represent.

So, if you looked between zero and 0.

5, you could see that there were one, two, three, four, five intervals.

0.

5 divided by five is equal to 0.

1.

So, each of these represents 0.

1, or a tenth of a kilogramme.

And then we had to go even smaller here.

So, we're looking at the gap between 0.

2 and 0.

3.

So, the difference between those two numbers is 0.

1.

And we're looking at one, two intervals.

So, 0.

1, the interval here divided by two is equal to 0.

05.

So, therefore, this jump here is 0.

2 plus 0.

05, which is equal to zero, sorry, which is equal to 0.

25.

So, arrow A points to 0.

25 kilogrammes.

Arrow B, we can see that this, if I label this on here, is halfway between 0.

5 and 0.

6.

Have a difference of 0.

1.

I'll do this over here.

0.

6 take away 0.

5 is equal to 0.

1.

And we're looking at intervals here, there are 10 of them.

So, 0.

1 divided by 10 is equal to 0.

01.

Each of these small lines here represent 0.

01.

So, B represent that six further on, so it's 0.

56.

And then, on to C.

We already know the value of these lines.

They represent jumps of 0.

1.

So, this would be 1.

5, 1.

6, 1.

7, 1.

8, 1.

9 kilogrammes.

On to question three.

And you had a container where the capacity changed.

So, if the capacity was one litre, where was the arrow pointing to? So, let's have a look first of all at how many intervals we have.

One, two, three, four, five, six, seven, eight.

So, if it was one litre, it would be one divided by eight, which is equal to 0.

125.

So, each of these will be 0.

125 litres.

And our arrow points to the first, second, third, fourth, fifth interval.

So, we'd have to multiply that by five, which gives us 0.

625 litres.

Now, what if it was five litres in capacity? Well, we'd just substitute five in here.

Five litres divided by eight is equal to 0.

625.

And we're looking for the fifth interval, so we would multiply that by five, which will give us 3.

125 litres.

Then if the capacity was 20 mils, all we do is substitute 20 in here.

We're still dividing it into eight intervals.

20 divided by eight is equal to 2.

5.

And you could just count up in 2.

5s, or you could do 2.

5 multiplied by five, which is equal to 12.

5 millilitres.

And then finally, 1/2 a litre.

1/2 a litre is equal to 500 millilitres, divided by eight is equal to 62.

5 millilitres, and multiplied by five equals to 312.

5 millilitres.

On to question four.

Again, we've got lots of different combinations here.

So, for the first one, what temperature is shown if A is zero and B is 16? Well, first of all, the difference between these two, 16 take away zero is 16.

The number of intervals is, we'll count the big ones.

One, two, three, four, five.

So, 16 divided by five, oh, sorry, not five, eight because we've got to go all the way up to B.

Five, six, seven, eight.

So, 16 divided by eight is equal to two.

And then we know that this is the fifth interval.

That's the error I made before.

So, that will be two, four, six, eight, 10 degrees.

So, if A was zero and B was 16, then the arrow will be pointing to 10 degrees because we know the value of each interval is two degrees.

So, if A was minus 13 degrees and B was minus five, the difference between the two, minus five take away minus 13 is eight.

and divide that by eight is equal to one.

So, each of these represents one degree.

If A was minus 13, then the arrow would be pointing to minus 12, minus 11, minus 10, minus nine, minus eight degrees C.

And then for this one, if A was five degrees, sorry, if A was minus five degrees and B was 35 degrees, then the difference there is 40.

And we're dividing it by eight, which means that each interval represents five.

If this was minus five, then we go to zero, five, 10, 15, 20 degrees.

And then finally, if A is minus eight and B is 72, the difference is 80 divided by eight is equal to 10.

So, each interval represents 10 degrees.

So, we go from minus eight and we would count round, and this interval here will be 42 degrees.

And now our final question.

On this scale, the arrow shows the weight of the pineapple.

Now, this is a question from a SATs paper.

Remember that we talked about weight and mass being used interchangeably.

Really, the correct mathematical term here would be mass rather than weight, but you need to be used to seeing it written as weight as well.

So, if this shows you the weight, then how, what.

Well, let's go back to mass.

If this scale shows you the mass of the pineapple, first of all, what is the mass of the pineapple? So, we're looking at between one and two is one, and we've got one, two, three, four, five, six, seven, eight, nine, 10 intervals.

One divided by 10 is equal to 0.

1.

So, each of these intervals represents 0.

1 kilogrammes.

So, then we need to add 0.

1 to one, so that would be 1.

1, 1.

2, 1.

3, 1.

4 kilogrammes.

So, the mass of the pineapple is 1.

4 kilogrammes.

Now, we've got a different scale, and we need to mark 1.

4 kilogrammes on it.

So, let's think about what is the scale going up in? We'll look between one and two.

There are one, two, three, four, five intervals this time.

One divided by five, sorry, is equal to 0.

2.

So, it's going up in jumps of 0.

2.

So this would be 1.

2, 1.

4.

So, that would be showing us the mass of the pineapple.

Okay, it's time for your final quiz.

So, pause the video and complete the quiz, and then click restart once you're finished.

Great work today, year six, you've done a really good job.

Now, in our next lesson, we'll be converting between standard units of length.

So, we'll be looking at millimetres to centimetres, and metres to kilometres.

I'm looking forward to seeing you then.